labs/05 - Incomplete and does not match source code

[jhogan05]

Readme.md incomplete (absent Source snippets x 3) at the end, and
no discussion on Controller folder / StateController.cs which is found in the source

Source code does not match Source code (lab/05..) displayed in Readme.md snippets:

• ISessionManager.cs -- GetSessionAync() vs GetSession() [ Client and Server projects]
• SessionManger.cs -- GetSessionAync() vs GetSession() / UpdateSessionAsync() vs UpdateSession [Client and Server projects]
• SessionIdManager.cs -- GetSessionIdAsync() vs GetSessionAsync()
• SessionManager.cs (Server) in Source code:
  • more modern constructor with dependency injection of SessionIdManger
  • in GetSessionAsync extra code from "var endtime... with the "while (session.IsCheckedOut)..{ }" loop in Readme.md
  • in UpdateSessionAsync extra code: "_session[key].IsCheckedOut = false;" in Readme.md
  • in Replace() code to shortcut if newSession / oldSession are the same (not in Readme.md)